CREATE  TABLE test.Names (
    id INT NOT NULL ,
    salary INT NULL ,
    name VARCHAR(45) NULL ,
    tmpl INT,
    PRIMARY KEY (`id`) ,
    UNIQUE INDEX `id_UNIQUE` (`id` ASC)
);

id,   salary, name, tmpl
1,    10,     John, null
2,    20,     Pat,  null
3,    30,     Jane, null

salary of each person/Sum(salary)*100

id,   salary, name, tmpl
1,    10,     John, 16.67
2,    20,     Pat,  33.33
3,    30,     Jane, 50

SET @sum_salaries = (SELECT SUM(salary) FROM test.Names);

UPDATE test.Names
SET tmpl = salary/@sum_salaries * 100;

SET @SallarySum = (SELECT SUM(salary) FROM TableName);

UPDATE Names t1
INNER JOIN
(
    SELECT id, (Salary / @SallarySum) * 100 tmpl
    FROM Names
) t2 ON t1.Id = t2.Id
SET t1.tmpl = t2.tmpl;

update `test`.`Names`
 set tmpl = salary / (select sum(salary) from `test`.`Names`) * 100
where tmpl is null --for multiple times execution